I've rewriten Atushi's fix for the 64-bit put_unaligned on 32-bit systems
bug to generate more efficient code.

This case has buzilla URL http://bugzilla.kernel.org/show_bug.cgi?id=5138.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>